Materials handling apparatus



Sept. 4, 1956 J BRUCE 2,761,263

MATERIALS HANDLING APPARATUS Filed Aug. 25, 195] 3 Sheets-Sheet 1 v Qua;rmrm1mregagggggxepgplmxmxmxmrmxmxml IN V EN TOR. JOHN K. BRUCE M am A T TORNE V p 4, 1955 J. K. BRUCE 2,761,263

MATERIALS HANDLING APPARATUS Filed Aug. 25, 1951 3 Sheets-Sheet 2 IN VEN TOR. JOHN A. BRUCE yMf/ZM .4 T TORNE V Sept. 4, 1956 J, BRUCE 2,761,263

MATERIALS HANDLING APPARATUS Filed Aug/25, 1951 5 Sheets-Sheet 5 (E -6H FIG. /0.

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A T TORNE V United States Patent Ofilice r 2,761,263 Patented Sept. 4, 1956 2,761,263 MATERIALS HANDLING APPARATUS John K. Bruce, South Pasadena, Calif., assignor to Bruce Engineering Corporation, San Francisco, Calif, a corporation of California Application August 25, 1951, Serial No. 243,693 17 Claims. (Cl. 53-24) This invention relates to materials handling equipment and more specifically improved apparatus for opening cartons. Whereas the apparatus of the invention is adapted to opening shipping cartons under varying circumstances, it is particularly useful for opening cartons of unfilled containers preparatory to removing the containers from the cartons. The invention is conveniently described hereinafter with relation to such use.

In many industries in which products are containerpacked, for example breweries, canneries, etc., empty containers are received from the manufacturers in cartons with side and end cover flaps unsealed. Each carton generally holds a plurality of containers, usually a dozen or more. Before these containers can be filled, sealed, labeled, etc., it is necessary that they be removed from the cartons in which they are received and disposed on conveyor lines for transport to the various packing operations. In copending United States patent application, Serial No. 153,724, filed April 3, 1950, by John K. Bruce and Thomas H. Davis, now U. S. Patent No. 2,685,975, apparatus for automatically and continuously removing containers from shipping car-tons was illustrated and described.

To remove containers from shipping cartons, and re gardless of the means employed, it is first necessary to fold the unsealed cover flaps of the carton outwardly to expose the containers. To accomplish this with the side flaps, i. e. the flaps hinged on a line parallel to the direction of travel of the carton on a conveyor, for example, is a comparatively simple matter. Conventionally, a pair of plows are mounted above and to the side of the conveyor to accomplish this function. In the apparatus described in the aforementioned copending application, auxiliary means were provided to initiate displacement of the side flaps to facilitate engagement thereof by the plows,

Manipulation of the end flaps of the carton is more difficult. Prior to the developments described in said copending application, it was the practice to alter the di rection of carton travel or to reorient the carton on the same conveyor after the side flaps had been plowed open and so as to align the end flaps with the direction of carton movement. In the apparatus described in the copending application, means were included for opening the end flaps while they were oriented transversely to the direction of carton travel. Such means obviates the complexities of multiple conveyor systems and in general expedites the operation.

The present invention is directed to improved means for opening the leading and trailing flaps of a carton as it travels on a conveyor and contemplates apparatus comprising conveyor means for cartons, a flap-engaging member suspended above said conveyor means, and means carrying said flap-engaging means at a velocity greater than the velocity of conveyor travel through a closed vertically oriented planar loop. The flap-engaging means travels continuously through this enclosed loop, the loop having a first leg in which the fiap-engaging means gaging finger, is continuous travels in the same direction as the conveyor, during which travel the leading end flap is engaged and folded forwardly of the carton. The loop has a second leg generally lying above the first leg in which the flapengaging means travels counter to the direction of conveyor travel and during which travel it engages the trailing flap of the carton folding it rearwardly therefrom. The loop also includes at least one additional leg closing the loop between the first and second. legs and during the major part of which the flap-engaging means is disengaged from the carton.

In the above described apparatus the flap-engaging means is conveniently a metal finger depending from a rod suspended transversely between oppositely mounted and aligned carrier chains. Each of the opposing carrier chains are, in one embodiment, carried over a number of sprockets oriented respectively to drive each of the chains and define the path of travel as above described. The chains are synchronously driven at a velocity greater than the velocity of conveyor travel and are synchronized with the placement of the cartons on the conveyor so that the flap-opening operation is automatic and continuous with the flap-engaging finger registering with each succeeding carton at the same point in its looped path.

An advantage of the invention resides in the fact that movement of the chains, and hence of the flap-enand at a constant speed. By elimination of interrupted or intermittent motion considerable saving is realized in the complexity of the apparatus involved and maintenance, and the difliculties of properly timing and synchronizing intermittent motion are obviated.

The invention will be more clearly understood from the following detailed description thereof taken in conjunction with the accompanying drawing wherein:

Fig. 1 is a plan view of the apparatus of the invention;

Fig. 2 is a longitudinal sectional elevation taken on the line 2- 2 of Fig. 1;

Fig. 3 is a transverse sectional elevation taken on the line 3-3 of Fig. 1;

Fig. 4 is a longitudinal sectional elevation taken on the line 44 of Fig. 3;

Fig. 5 is a longitudinal sectional elevation taken on the line 5-5 of Fig. 3;

Fig. 6 is a longitudinal sectional the line 66 of Fig. 3; and

Figs. 7 through 13 show diagrammatically succeeding stages in the operation of opening the leading and trailing flaps of the carton with the flap-engaging means being at a different position in its closed path in each of the suc ceeding stages.

Referring to Figs. 1, 2 and 3, the apparatus as illustrated includes a framework 10. In most instances the flap-opening mechanism described in the present application will be used in conjunction with other mechanisms in a unitized apparatus for removing containers from cartons for example, in which case the framework 10 elevation taken on will conveniently constitute the framework for the entire apparatus and will be utilized lar apparatus herein described. A ed in the apparatus to carry cartons. 13, 14, etc. Two drive chains 16, 18 are supported inwardly from the to support the particuframework 10 above and adjacent the opposite sides of conveyor 12 is mountsuch as to impart a looped configuration to the chain with a first 'leg between the sprockets 21 and 25 lying parallel to the surface of the conveyor 12 through which the chain travels in the same direction as the conveyor. The chain is carried over the sprocket 25 into a second leg of the loop lying between the sprocket 25 and the sprocket 22 and between sprockets 23, 24 lying intermittent the sprockets 25, 22. in this second leg of the loop the chain travels counter to the direction of travel of the conveyor and above the first leg of the loop. The second leg is oifset by the sprockets 23, 24 for the purpose hereinafter described. The chain is carried over the sprocket 22 into a third leg lying between the sprocket 22 and the sprocket 26 and over the sprocket 26 into a fourth leg lying between the sprocket 26 and the sprocket 20. The sprocket lies vertically above the sprocket 21, the chain being carried over the sprockets 2t) and 21 back to the first leg of the loop.

The distance of chain travel between the sprocket 22 and the sprocket 20 is predetermined as a function of the timing required which, in turn, is a function of the velocity of the conveyor 12 and of the chain and of the spacing of the carton on the conveyor 12.

Each of the sprockets 20, 21, 22, etc. are rotatably mounted on shafts projecting inwardly from the framework 10. A shaft 30 is mounted between the opposite sides of the framework 10 extending beneath the conveyor 12 and has a drive sprocket 32 mounted thereon adjacent one side. This sprocket is connected by means of a chain 33 to the drive system for the entire apparatus (the dr've system not being shown) or to a separate drive system if desired. The shaft 32 carries a pair ofidentical sprockets 34, 35 adjacent opposite ends which are, in turn, linked by chains 36, 37 respectively to driving sprockets 38, 39 respectively carried on a shaft supporting one of the several chain sprockets. Referring to Fig. 2, the drive sprocket 38 (not shown in the figure) and the chain sprocket 22 are mounted on a common shaft 40. By this means both of chains 16 and 18 are driven in synchronism at a rate determined by the ratio between the drive and driving sprockets.

A rod 44 is mounted between the chains 16, 18 and is rotatable therebetween on its longitudinal axis through a limited angle. Referring to Figs. 3 and 5, a chain lug 46 is mounted on the chain 18 and the rod44 is rotatably journalled in the lug 46. A collar 47 is afiixed to the rod 44 by a set screw 48 adjacent the lug'46 and a helical spring 49 is carried over the rod and is anchored at one end to the lug 46 and at the other end to the collar 47 to load the shaft against rotation about its longitudinal axis.

Referring to Figs. 3 and 6, the rod 44 is differently mounted to the opposite chain 16. A chain lug 52 is mounted on the chain 16 in substantially the same manner as the lug 46. The corresponding end of the rod 44 has an elongated bore in which is mounted a bullet pin 53 spring-loaded with a helical spring 54. The outer end of bullet pin 53 is journalled in the lug 52 and has a coaxial bore to allow the pin to engage over chain pin 56 which is likewise journalled in the lug 52. The arrangement described is not essential to the operation of the apparatus but greatly facilitates assembly and disassembly, it being possible to remove the rod simply by depressing the bullet pin 53 inwardly against the loading of spring 54 to disengage the rod from the chain pin 56 and lug 46.

Referring to Figs. 3 and 4, a flap-engaging finger 60 is mounted to the rod 44 in the following manner: A collar 61 is mounted on the rod with a set screw 62 and the finger 60 is rotatably journalled on the shaft. A helical spring 63 disposed around the rod is anchored at one end to the collar 61 and at the opposite end to the finger 60, so that the finger 60 is loaded against rotation about the rod 44. The finger 60 is aflixed to a hub 64, likewise rotatably mounted on the rod 44.

A collar 66 is rigidly afiixed to the rod by a set screw 67 and includes a wedge-shaped recess 68 adjoining the hub 64. A stop pin 70 is mounted in the hub 64 and projects into the recess 68 and is held against the collar by the loading spring 63.

The purpose of mounting the flap-engaging finger 60 to the rod 44 in the described manner is to provide an automatic release mechanism to avoid breakage in the event of jamming or other operational difiiculty. Although the normal position of the finger 60 is determined by abutment of the finger '70 against the collar 66, the finger can swing out of this position against the loading of spring 63, as for example into the dotted line position shown in Fig. 4, if for any reason it becomes jammed against a carton or foreign object on the conveyor.

A cam follower 72 is mounted on and adjacent an end of the rod 44 and closely proximate to the chain 16. The cam follower 72 includes a roller 73 and a stop pin 74. The pin 74, as shown in Figs. 3 and 6, normally abuts the chain lug 52 and fixes the angular position of the rod which is loaded in this position by the spring 49. Referring again to Fig. 2, a first cam 76 is mounted in the path of the cam follower 72 intermediate the vertically aligned sprockets 2t), 21 over which the chain 16 is carried. The effect of displacement of the cam follower 72 by engagement of the roller 73 with the cam 76 is to rotate the rod 44 and as a consequence the finger 60 away from its loaded position. The normal position of the finger with respect to the carrying chains is generally parallel to and projecting in the direction of the travel of the chains. When the cam follower and specifically the roller 73 engages the cam 76, the rod 44 is rotated clockwise (as viewed in Fig. 2) through a small angle to facilitate engagement of the finger under the leading flap of the carton. With reference to Fig. 2, the finger is displaced to project downwardly toward the carton 14 while the supporting rod is yet moving downwardly between the sprockets 2t) and 21. As the portion of the chain, to which the rod 44 is attached, carries around the sprocket 21 and begins to travel in the direction and parallel to the conveyor, the finger 60 will remain in the downwardly projecting position as it is spring-loaded in this position with respect to chain travel between the sprockets 21 and 25.

A second cam 80 is mounted in position to engage the cam follower 72 intermediate the sprockets .21 and 25, that is while the finger 60 and support rod 44 are traveling parallel to and in the same direction as the conveyor 12. Engagement of the cam follower 72 with the cam 80 has the effect of rotating the finger 60 clockwise, as viewed in Fig. 2, so that after engagement under the leading flap of the carton 14 it will raise this flap and displace it outwardly from the carton, all as more clearly described with relation to Figs. 7 through 13.

A second rod 82 is connected between the chains 16 and 18 and trails the rod 44 with respect to direction of chain travel. The rod 82 acts to hold the trailing flap of the carton in the outwardly folded position after it has been opened by the flap-engaging finger 60, all as described in greater detail hereinafter.

In a preferred embodiment, the flap-engaging finger 60 is positioned with relation to carton-positioning on the conveyor so as to extend into the carton between adjoining rows of containers and conveniently between central adjoining longitudinal container rows. This is not a necessary feature of the invention but is a desirable one since it permits use of a sufficiently long finger to insure positive engagement with the flaps and to achieve greater displacement of the flaps in the process of folding them outwardly from the carton. For this purpose the finger is mounted midway between the sides of the conveyor, and guide baffles 84, 85 are positioned longitudinally at opposite sides of the conveyor to center cartons on the center line of the conveyor.

The operation of the apparatus can best be understood by reference to the diagrams of Figs. 7 to 13, which show succeeding stages in the operation. Referring first to Fig. 2, the flap-engaging finger 60 is deflected by engagement of the cam follower 72 with the cam 76 so as to project downwardly toward the carton (carton 14 in this case) as rod 44 approaches the sprocket 21. In this position the finger 60 engages under the leading flap of the carton 14 and is displaced downwardly deeper into the carton as the rod 44 is carried around the sprocket 21. Referring to Fig. 3, as the cam follower 72 engages the cam 80, the finger 60 is rotated clockwise to lift the leading flap upwardly from the carton. Referring to Fig. 8, clockwise rotation of the finger continues until it achieves the position shown in Fig. 8 and remains in this position as the cam follower roller 73 travels across the horizontal portion of the cam 80. Since the drive chains are traveling faster than the conveyor 12, the finger 60, engaged with the leading flap of the carton, folds the flap upwardly and outwardly from the carton and at the position shown in Fig. 8 the flap extends outwardly from the carton at an angle of about 30.

Referring to Fig. 9, as the cam follower 72 passes the cam 80 the finger begins counter-clockwise rotation to return it to its spring-loaded position, and in so doing completes the displacement of the leading flap outwardly from the carton. This flap engages under a conveyor 88 which forms a part of a succeeding stage of the apparatus described in the aforesaid .co-pending application.

If the flap-opening mechanism in the present invention is used in conjunction with other forms of handling equipment, some means equivalent to the conveyor 88 will be required to hold the leading flap of each succeeding carton in the outwardly folded position as the flap-engaging finger is carried out of engagement with the flap.

Referring to Fig. 10, the finger-supporting rod 44 has traveled around the sprocket 25 into the second leg of the loop and is in the process of engaging under the trailing flap of the carton as it dips between sprockets 23 and 24. In Fig. 11 the rod 44 is traveling between the sprockets 23 and 22 and in so doing causes the finger 60 to fold the trailing flap upwardly from the carton.

As the rod 44 travels around the sprocket 22 it carries the finger 60 out of engagement with the carton flaps, the finger remaining thus disengaged until it returns to the position shown in Fig. 2. However, and as shown in Fig. 12, as the finger 60 disengages from the trailing flap, the shaft 82, which trails the finger, engages against and holds the trailing flap of the carton in the upwardly extending position.

With reference to Fig. 13, the rod 82 so retains the trailing flap of the carton throughout the third leg of the conveyor 88, the trailing flap the carton.

The apparatus as described is continuous and is driven by simple belt, chain or gear connection between a prime mover for an entire apparatus unit or by a separate moti- In preferred practice the mechanism of the invention is driven responsive to the means driving the conveyor 12, since synchronism between the mechanism and the conveyor is thus easily achieved. Such matched operation is, of course, essential if continuity is to be achieved, since the flap-engaging finger must engage with succeeding cartons at exactly the same stage when it has traversed the described closed loop.

complicated timing mechanism, brakes. Substantially the only moving parts are the two chains looped over a number of sprockets, such a chain system being exceedingly rugged and durable. The rod on which the flap-engaging finger is mounted rotates through only a comparatively small angle against loading springs and has no appreciable load no problem of bearing surfaces. The finger itself is employed under conditions of substantially no load so that there is no appreciable danger of breakage or wear on the finger. The only possible condition of damage is taken into consideration in the safety release mechanism through which the finger is mounted to its supporting rod. It is apparent, therefore, that the invention provides rugged, simple and durable means for continuously and rapidly opening the end flaps of a carton without requiring reorientation of the carton in any manner.

I claim:

1. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, a flap-engaging means suspended above the conveyor means, and carrier means carrying the flap-engaging means through a closed vertically oriented planar loop having a first leg so oriented relative to the conveyor that the flap-engaging means travels in the same direction as the conveyor means, a second leg above the first so oriented relative to the conveyor that the flap-engaging means travels counter to the conveyor and at least one additional leg closing the loop between the second and first legs, the first and second legs of the loop being so spaced above the conveyor that the flap-engaging means extends into the underlying carton through at least a part of its travel along each of these two legs.

2. Apparatus according to claim 1 wherein said carrier means comprises a pair of individual conveyors disposed in identical configuration on opposite sides of said conveyor means, a rod connected between said conveyors and means suspending said flap-engaging means from said rod.

3. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, a flap-engaging means suspended above the conveyor means, carrier means means travels in the same direction as the conveyor and at least one additional leg closing the loop between the third and first legs, the first and second legs of the loop being so spaced above the conveyor that the flap engaging means extends into the underlying carton through at least a part of its travel along each of these two legs, means driving the carrier means at a velocity in excess of that of the conveyor, and means for holding the flaps in the opened position.

4. Apparatus according to claim 3 wherein the means for holding said flaps in the opened position comprises in part a rod suspended transversely above the conveyor and mounted to travel with and trailing the flap engaging means.

5. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, a flap-engaging means suspended above the conveyor means, carrier means carrying the flap-engaging means through a closed vertically oriented planar loop having a first leg in which the flap-engaging means travels in the same direction as the conveyor, a second leg above the first .in which the flap-engaging means travels counter to the conveyor and at least one additional leg closing the loop between the second and first legs, the first and second legs being so spaced above the conveyor that the flap-engaging means projects into the carton disposed on the conveyor through at least a part of each of said legs, and means driving the carrier means at a velocity in excess of that of the conveyor.

6. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, -a flap-engaging means suspended above the conveyor means, carrier means carrying the flap-engaging means through aclosed vertically oriented planar loop having a lower leg so oriented relative to the conveyor that the flap-engaging means travels in .the same directionas the conveyor, an upper leg so oriented relative to the conveyor that the flap-engaging means travels counter to the conveyor and at least one additional leg closing the loop between the upper and lower legs, the first and second legs of the loop being so spaced above the conveyor that the flapengaging means extends into the underlying carton through at least a part of its travel along each of these two legs, means driving the carrier at a velocity in excess of that of the conveyor, and means causing the flapengaging means to rotate responsive to its linear motion and after successive engagement with the leading and trailing flaps of the carton.

7. Apparatus according to claim 6 wherein the means for causing said flap-engaging means to rotate comprises spaced cams and a cam follower interconnected totravel in the path of and with the fiap'engaging means and oriented to engage the cams.

8. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, a separate drive chain mounted adjacent each side and above the conveyor over a number of spaced sprockets, each chain being carried in a closed vertically disposed planar loop corresponding to that of the other chain and having a first leg in which the chain travels parallel to and in the same direction as the conveyor, 21 second leg above the first in which the chain travels generally counter to the conveyor, at least one additional leg joining the second and first legs, a rod rotatably mounted between the chains to be carried through said closed loop by the chains, an elongated finger mounted to and projecting perpendicularly from the rod, the first and second legs of the loop being so spaced above the conveyor that the elongated finger extends into the underlying carton through at least a part of its travel along each of these two legs, first means operable responsive to linear motion of the rod in said additional leg to cause rotation of the rod and the finger in the direction of chain travel in the first leg, second means operable responsive to linear motion of the rod in the first leg to cause rotation of the rod and the finger upwardly from the conveyor, and means driving the chains synchronously at a predetermined velocity exceeding that of the conveyor.

9. Apparatus for opening cover flaps of a carton com prising conveyor means for the carton, a separate drive chain mounted adjacent each side and above the conveyor over a number of spaced sprockets, each chain being carried in a closed vertically disposed planar loop corresponding to that of the other chain and having a first leg in which the chain travels parallel to and in the same direction as the conveyor, a second leg above the first in which the chain travels generally counter to the conveyor, and at least one additional leg joining the second and first legs, a rod rotatably mounted between the chains to be carried through the closed loo-p by the chains, an elongated finger mounted to and projecting perpendicularly from the rod, the first and second legs of the loop being so spaced above the conveyor that the elongated finger extends into the underlying carton through at least a part of its travel along each of these two legs, a cam follower mounted to and adjacent one end of the rod, a first cam mounted adjacent the beginning of the first leg to cause rotation of the rod and the finger in the direction of chain travel in the first leg, a second cam mounted along the first leg to cause rotation of the rod and the finger upwardly from the conveyor, and means driving the chains synchronously at a predetermined velocity exceeding that of the conveyor.

10. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, a separate drive chain mounted adjacent each-side and above the conveyor over a number of spaced sprockets, each chain being carried in'a closed vertically disposed planar loop corresponding to that of the'other chain and having a first leg in which the chain travels parallel to and in the same direction as the conveyor, a second leg above the first in which the chain travels generally counter to the conveyor, a third leg above the second in which the chain travels in the same direction as the conveyor and a fourth leg joining the third and first legs, a first rod rotatably mounted between the chains to be carried through said closed loop by the chains, an elongated finger mounted to and projecting perpendicularly from the red, the first and secondlegs of the loop being so spaced above the conveyor that the elongated finger extends into the underlying carton through :at least a part of its travel along each of these two legs, a cam follower mounted to and adjacent one end of the rod, a first cam mounted adjacent the beginning of the first leg to cause rotation of the rod and the finger in the direction of-chain travel in the first leg, a second cam mounted along the first leg to cause rotation of the rod and the finger upwardly from the conveyor, a second rod mounted between the chains and trailing the first rod, and means driving the chains synchronously at a-predetermined velocity exceeding that of the conveyor.

11. Apparatus for opening cover flaps of a cartoncomprising conveyor means for the carton, a separate drive chain mounted adjacent each side and above the conveyor over a number of spaced sprockets, each chain being carried in a closed vertically disposed planar loop corresponding to that of the other chain and having a first leg in which the chain travels parallel to and in the same direction as the conveyor, a second leg above the first in which the chain travels generally counter to the conveyor, a third leg above the second in which the chain travels in the same direction as the conveyor and a fourth leg joining the third and first legs, a first rod rotatably mounted between the chains to be carried through said closed loop by the chains, an elongated finger mounted to and projecting perpendicularly from the red, the first and second legs of the loop being so spaced above the conveyor that the elongated finger extends into the underlying carton through at least a part of its travel along each of these two legs, a cam follower mounted to :and adjacent :one end of the rod, a first cam mounted adjacent the beginning of the first leg to cause rotation of the rod and the finger in the direction of chain travel in the first leg, a second cam mounted along the first leg to cause rotation of the rod and the finger upwardly from the conveyor, a second rod mounted between the chains and trailing the first rod, means mounted above the conveyor and forwardly of the path of said rods to retain the flaps in the opened position, and means driving the chains synchronously at apredetermined velocity exceeding that of the conveyor.

12. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, a separate .drive chain mounted adjacent each side and above the conveyor over a number of spaced sprockets, each chain being carried in a closed vertically disposed planar loop corresponding to that of the other chain and having a first leg in which the chain travels parallel to and in the same direction as the conveyor, a second leg above the first in which the chaain travels generally counter to the conveyor, a third leg above the second in which the chain travels in the same direction as the conveyor and a fourth leg joining the third and first legs, a first .rod, means rotatably securing the rod between the chains to be carried through said closed loop by the chains, an elongated .finger mounted to and projecting perpendicularly from the rod, the first andsecond legs of the loop being so spaced above the conveyor that the elongated finger extends into the underlying carton through at least a part of its travel along each of these two legs, a cam follower mounted to and adjacent one end of'the rod, a first cam mounted adjacent the beginning of the first leg to cause rotation of the rod and the finger in the direction of chain travel in the first leg, a second cam mounted along the first leg to cause rotation of the rod and the finger upwardly from the conveyor, a second rod mounted between the chains and trailing the first rod, and means driving the chains synchronously at a predetermined velocity exceeding that of the conveyor.

13. Apparatus according to claim 12 wherein the means rotatably mounting the rod to the chains comprises a first chain lug mounted to one of the chains with one end of the rod journalled therein, a collar mounted on the rod adjacent said one end, a helical spring mounted on the rod and anchored at opposite ends to the lug and collar, a second lug mounted over chain pins protruding from the other of the chains, a bullet pin disposed in the opposite end of the rod and protruding therefrom, the bullet pin being journalled in the lug and having a longitudinal bore in its outer end to receive one of the chain pins.

14. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, a separate drive chain mounted adjacent each side and above the conveyor over a number of spaced sprockets, each chain being carried in a closed vertically disposed planar loop corresponding to that of the other chain and having a first leg in which the chain travels parallel to and in the same direction as the conveyor, a second leg above the first in which the chain travels generally counter to the conveyor, a third leg above the second in which the chain travels in the same direction as the conveyor and a fourth leg joining the third and first legs, a first rod rotatably mounted between the chains to be carried through said closed loop by the chains, an elongated finger mounted to and projecting perpendicularly from the rod and releasably held against rotation relative to the red, the first and second legs of the loop being so spaced above the conveyor that the elongated finger extends into the underlying carton through at least a part of its travel along each of these two legs, a cam follower mounted to and adjacent one end of the rod, a first cam mounted adjacent the beginning of the first leg to cause rotation of the rod and the finger in the direction of chain travel in the first leg, a second cam mounted along the first leg to cause rotation of the rod and the finger upwardly from the conveyor, a second rod mounted between the chains and trailing the first rod, and means driving the chains synchronously at a predetermined velocity exceeding that of the conveyor.

15. Apparatus according to claim 14 wherein the finger is journalled on the rod and includes a hub journalled on the rod, a first collar afiixed to the rod on one side of the finger adjacent the hub and having a notch in the periphery thereof, a stop pin mounted to the hub and projecting into the notch, a second collar afiixed to the rod on the opposite side of the finger, a helical spring mounted on the rod and anchored at opposite ends to the collar and the finger to load the pin in the notch engaging position.

16. Apparatus for opening cover flaps of a carton comprising conveyor means for the carton, a flap-engaging means suspended centrally above the conveyor means, carrier means carrying the flap-engaging means through a closed vertically oriented planar loop having a first leg in which the flap-engaging means travels in the same direction as the conveyor, a second leg above the first in which the flap-engaging means travels counter to the conveyor and at least one additional leg closing the loop between the first and second legs, the first and second legs of the loop being so spaced above the conveyor that the flap-engaging means extends into the underlying carton through at least a part of its travel along each of these two legs, means driving the carrier means at velocity in excess of that of the conveyor, and means centering the cartons on the conveyor so that the flap-engaging means will project into the carton midway between its sides.

17. Apparatus for opening cover flaps of a carton com prising conveyor means for the carton, longitudinal guide members holding the carton against transverse movement on the conveyor, a separate continuous link chain looped over spaced sprockets at each side and above the conveyor, each chain lying in a vertical plane and the two chains being in transverse alignment with each chain loop having a first lower leg in which the chain travels in the same direction as the conveyor, a second upper leg in which the chain travels counter to the conveyor and dips toward the conveyor at a point in said leg and at least one additional leg joining the end of a second leg to the beginning of the first leg, a first rod rotatably mounted between the chains, spring-loading means holding the rod against rotation, an elongated finger mounted to and projecting perpendicularly from the rod, the first and second legs of the loop being so spaced above the conveyor that the elongated finger extends into the underlying carton through at least a part of its travel along each of these two legs, a cam follower mounted on the rod adjacent one end thereof, a first cam disposed adjacent the beginning of the first leg and engageable by the cam follower to rotate the rod to a position with the finger projecting downwardly and forwardly, a second cam disposed approximately midway of the first leg and engageable by the cam follower to rotate the rod to a position with the finger extending upwardly and forwardly, a second rod mounted between the chains and trailing the first rod, and means driving the separate chains synchronously and at a velocity in excess of that of the conveyor.

References Cited in the file of this patent UNITED STATES PATENTS 

